Transparent, electrically conductive enclosure



June 26, 1962 TRANSPARENT, ELECTRICALLY CONDUCTIVE ENCLOSURE l. E. BRADY 3,041,436

Filed Aug. 11, 1960 IRVING E. BRADY INVENTORL ATTORNEYS United States Patent 3,041,436 TRANSPARENT, ELECTRICALLY CONDUCTIVE ENCLOSURE Irving E. Brady, Glendale, Califi, assignor to The Sierracm Corporation, Burbank, Califi, a corporation of California Filed Aug. 11, 1960, Ser. No. 49,002 Claims. (Cl. 219-19) This invention relates to transparent, electrically conductive enclosures such as Windshields and windows for aircraft and other vehicles.

Transparent, electrically conductive windshield panels are being used extensively in the fabrication of aircraft and automotive Windshields and windows for anti-fogging and anti-icing applications. The fabrication and installation of the electrical hardware for such devices presents many problems, among which is providing the electrical connections for the lead-in wires. The primary object of the present invention is to provide a novel terminal block assembly for use in electrically conductive panels such as transparent, conductive Windshields for aircraft.

Another object of the present invention is to provide a terminal block assembly which permits soldering of the lead wire or wires while the assembly is in place in a panel without damage to the heat-sensitive plastic material used in making up the panel.

Other objects and advantages of this invention it is believed will be readily apparent from the following detailed description of preferred embodiments thereof when read in connection with the accompanying drawing.

In the drawing:

FIGURE 1 is a plan view of a windshield panel embodying the present invention.

FIGURE 2 is an enlarged fragmentary sectional view taken from the general area of FIGURE 1 indicated by the line 22.

FIGURE 3 is a sectional view taken on the line 33 of FIGURE 2.

FIGURE 4 is a perspective view of the terminal block assembly of the present invention.

FIGURE 5 is a perspective view of the metal insert portion of the terminal block assembly.

FIGURE 6 is a perspective view of another forming of terminal block assembly.

FIGURE 7 is a perspective view of one of the metal inserts forming a part of the assembly of FIGURE 6.

Referring now to the drawing, the terminal block assembly of the present invention is illustrated as installed in a transparent, electrically conductive aircraft windshield panel 10, the panel comprising a plastic laminate consisting of an outer face sheet '11, an interlayer 12 and an inner ply 13. The inner side of the face sheet 11 is coated with a transparent, electrically conductive coating 13a in electrical contact with one of a pair of metal bus bars 14. A conventional bumper strip 15 is also utilized.

Means are provided for electrically connecting the'bus bars to an external source of current and as shown, these means include a pair of terminal block assemblies 20. Each assembly comprises a generally rectangular body 'portion of plastic or other nonconducting material,

preferably a fiber-filled acrylic, the body portion carrying a molded insert 26 of aluminum or other metal. It will be seen from the drawing that the body portion surrounds all but the top face of the insert so that when the terminal block assembly is installed in the pre-cut slot 30 provided in the inner ply, the insert is completely insulated from the inner ply. The terminal block assembly is preferably secured to the inner ply by means of a suitable adhesive.

The metal insert 26 is provided with a hole aligned with a hole 36 in the bottom of the body member, these "ice holes being in turn aligned with a hole 37 in the inner ply. A lead-in wire 40 is molded into the interlayer 12 in electrical contact with the bus bar 14 and extends through the holes 37, 36 and 35, being electrically connected to the metal insert by means of solder 50. A tapped hole 51 in the metal insert completes the assembly, the hole being adapted to receive an attaching screw (not shown) for the lead Wire from the current supply.

The terminal block assembly 60 is similar to the assemblies 20 described above, but is provided with a pair of metal inserts 61 in the plastic body member 62. Each insert is provided with a feed-through hole 63 for the reception of one of a pair of lead-in wires 64 to a sensing element 65. Each insert is also provided with a tapped hole 70 for attachment of the external lead wires of the sensing circuit (not shown).

The terminal block assemblies of the present invention provide rigid, fool-proof electrical connection means, permitting easy installation of the electrical hook-up. The fiber-filled body portions function as insulators during the soldering operation to prevent softening of the surrounding material of the inner ply which has a heat distortion point lower than the liquid temperature of soft solder.

The disclosed embodiment is not to be construed as a limitation upon my invention the scope of which is deemed to include any desirable constructive modification within the spirit and breadth of the appended claims.

I claim:

1. A transparent, electrically conductive enclosure comprising a pair of transparent face sheets with a transparent interlayer interposed therebetween, the inner side of one of said face sheets having a transparent, electrically conductive coating thereon; a terminal block assembly operably connected to one of said face sheets, said terminal block assembly comprising a body member of thermally non-conductive material, a metal insert, said insert being surrounded on all sides but one by said body member, said body member and said insert having walls forming coaxial holes extending therethrough; a lead wire extending through said holes into electrical contact with said conductive coating, said lead wire being soldered to said walls of said metal insert; and means on said metal insert for attaching an external lead wire thereto.

2. The apparatus of claim 1 wherein said body member is formed of fiber-filled plastic material.

3. A transparent, electrically conductive enclosure comprising outer and inner transparent face sheets having a transparent inter-layer interposed therebetween, the inner side of said outer face sheet having a transparent, electrically conductive coating thereon, said inner face sheet having a slot therein; a terminal block assembly inserted in said slot, said terminal block assembly comprising a body member of thermally non-conductive material, a metal insert, said insert being surrounded on all sides but one by said body member, said body member and said insert having walls forming coaxial holes extending therethrough; a lead wire extending through said holes into electrical contact with said conductive coating, said lead wire being soldered to said walls of said metal insert; and means on said metal insert for attaching an external lead wire thereto.

4. The apparatus of claim 3 wherein said body member is formed of fiber-filled plastic material.

5. The apparatus of claim 3 wherein said lead wire is molded into said interlayer.

References Cited in the file of this patent UNITED STATES PATENTS 1,563,211 MacInnes Nov. 24, 1925 2,509,701 Smith May 30, 1950 2,552,955 Gaiser et al. May 15. 1951 

